For purposes of this application, the term “linear tension member,” which may also be referred to as the “tension member,” is used to identify the workpiece with which applications of the device will be found. The linear tension member will be understood to encompass ropes, cables, chains and other equivalents. A variety of linear tension members are commonly used, especially in nautical applications, such as to secure a nautical vessel to a dock or similar support structure. Securing such vessels to a dock, for instance, typically requires that knots be tied in the rope. Occasionally, as during inclement weather, it may be difficult to tie the rope as described.
The inventor herein is also the inventor of U.S. Pat. No. 6,672,237 (“Hillier '237”), which describes a device that is useful in retaining a rope or cable, particularly in a nautical application, relative to a surface. The Hillier '237 patent is incorporated by reference as if fully recited herein, especially with regard to its teachings about the prior art that existed before its filing date.
The Hillier '237 device includes a base with a socket for receiving a plunger. A coil spring exerts an upward bias in the socket against the plunger. The base and the plunger each have circular apertures that may be selectively axially aligned when the plunger is depressed against the upward bias, but which are not axially aligned when the upward bias is unopposed.
Because the apertures have closed circular perimeters, an end of the linear tension member must be passed axially through the respective apertures while the plunger in depressed to align the apertures. When the depressing force is released, a shearing force is applied to the linear tension member from the axial misalignment, which frictionally secures the tension member within the device.
In order to secure an object using a linear tension member, the linear tension member is normally attached at one end to the object and at the other end to a fixed support structure. The tension member is normally attached by means of tying an end of the tension member on both the object and the support structure. In many cases, tightening (or loosening) a tension member that is already secured at both ends requires one of the ends to be untied, and, indeed, the Hillier '237 device requires that an end of the tension member be passed through the apertures.
In addition to being unable to accommodate tension members of differing diameters, the known prior art has not provided a device for loosening or tightening a tension member using only access to an intermediate portion of the tension member.